Datasheet

Section 23A Clock Pulse Generator
(H8S/2633, H8S/2632, H8S/2631, H8S/2633F)
R01UH0166EJ0600 Rev. 6.00 Page 997 of 1434
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
Table 23A.2 Damping Resistance Value
Frequency (MHz) 2 4 8 12 16 20 25
R
d
(Ω) 1 k 500 200 0 0 0 0
Crystal Resonator: Figure 23A.3 shows the equivalent circuit of the crystal resonator. Use a
crystal resonator that has the characteristics shown in table 23A.3.
XTAL
C
L
AT-cut parallel-resonance type
EXTAL
C
0
LR
s
Figure 23A.3 Crystal Resonator Equivalent Circuit
Table 23A.3 Crystal Resonator Parameters
Frequency (MHz) 2 4 8 12 16 20 25
R
S
max (Ω) 500 120 80 60 50 40 40
C
0
max (pF) 7 7 7 7 7 7 7
Note on Board Design: When a crystal resonator is connected, the following points should be
noted:
Other signal lines should be routed away from the oscillator circuit to prevent induction from
interfering with correct oscillation. See figure 23A.4.
When designing the board, place the crystal resonator and its load capacitors as close as possible
to the XTAL and EXTAL pins.
C
L2
Signal A Signal B
C
L1
H8S/2633 Group
XTAL
EXTAL
Avoid
Figure 23A.4 Example of Incorrect Board Design